how much compression?

[desert1]

my comp.

Compression on the 79 after sitting outside for a couple of years with the rings rusted to the sides of the cylinders were as follows
#1 90 lbs. #2 125 lbs. #3 125 lbs. #4 135 lbs.

This was a cold engine, unlubricated.....with oil comp. rose dramatically.


By the way, I removed each sparkplug and gave each piston a sharp rap using a brass rod and hammer to free the pistons in the bores then used the kickstart to turn it over a few times then used the starter motor.

Bruce

[Geezer]

Re: my comp.

Originally posted by desert1
Compression on the 79 after sitting outside for a couple of years with the rings rusted to the sides of the cylinders were as follows
#1 90 lbs. #2 125 lbs. #3 125 lbs. #4 135 lbs.

This was a cold engine, unlubricated.....with oil comp. rose dramatically.

By the way, I removed each sparkplug and gave each piston a sharp rap using a brass rod and hammer to free the pistons in the bores then used the kickstart to turn it over a few times then used the starter motor.

Bruce

For what it's worth, I came up with a very good way of unsticking an engine. Remove the tank and carbs and do this procedure outside with a fire extinguisher handy. Fill the cylinders with automatic transmission fluid and then heat the cylinders with a propane torch. For most singles and twins, 1 torch is enough. For larger engines 2 or more will be needed. The largest engine I’ve done this on was a 1976 CB750 and I used 2 torches (with a helper manning the second torch) and a propane heater to help keep it warm.

Don’t use the kick starter to turn the engine over. I used a large strap wrench on the alternator rotor.

After about an hour of warming the engine up, take the spark plugs out and reef on the strap wrench. If you’re having a 105+ degree day, you can substitute setting it in the sun for a few hours then follow up with 15 minutes with a torch. I’ve also put the bike in gear an rocked it back and forth after this to get it free. One more warning, it’s gonna shoot ATF all over the place when it breaks free so don’t be wearing your best blue jeans

Geezer

[DEmily]

Greezer,

That is the way my father taught me to loosen old engines, except he used the sun and about half a day of soaking. He is a big fan of ATF. Infact, he puts a quart in his oil and drives his old dodge pickup for a hundred mile or so be for he does his spring oil change. Says it cleans out the junk and kept the rubber seals limber. I don't do that on mine, but his oil dooge has been going forever. 270K plus on it, still running good. .

[Geezer]

Originally posted by DEmily
Greezer,

That is the way my father taught me to loosen old engines, except he used the sun and about half a day of soaking. He is a big fan of ATF. Infact, he puts a quart in his oil and drives his old dodge pickup for a hundred mile or so be for he does his spring oil change. Says it cleans out the junk and kept the rubber seals limber. I don't do that on mine, but his oil dooge has been going forever. 270K plus on it, still running good. .

ATF in the oil is an old trick to quite down noisy lifters in a V8. I've always heard it referred to as a last ditch effort on a really messed up engine. It's interesting to note that it's not necessarily so. In more recent years I’ve taken it on good authority that ATF is good gun oil and I used it exclusively for that purpose. I also have a formula for a powerful cleaning solvent that is ¼ ATF. It's good stuff and only a buck and a half a bottle.

I don't know how hot it gets in your area, but when unsticking an engine, I like to get the jugs up to around 200 degrees. A hot summer day only takes it half way (here in Oregon any way.)

Geezer